4 wheel drive issue

It sounds like you are driving in 4WD on dry pavement which is a big no-no. That will make the drive train bind up on turns and damage the transfer case . 4WD is for off road or snow and ice.

Ya, I know about the limited usage. I really only use it in the winter when it snows and the roads are icy and the 400lbs of sand in the back of my truck doesn't cut the mustard. In fact I haven't really used it at all the last couple of years because up in ND the last two winters have been pretty mild with little show. That's why I was asking the question. I used it a week or so ago with the first snow and noticed the whine and the clunk/bump, then used it again when it snowed this weekend and it did it again. I was more wondering if there is a problem with my transfer case that I need to go get checked out and what it might be...